Cooling structure of turbine airfoil
First Claim
1. A cooling structure of a turbine airfoil which cools a turbine airfoil exposed to hot gas using cooling air of a temperature lower than that of the hot gas,the turbine airfoil comprising an external surface exposed to the hot gas, an internal surface opposite to the external surface and cooled by the cooling air, a plurality of film-cooling holes extending between the internal surface and the external surface and blowing the cooling air from the internal surface toward the external surface to film-cool the external surface, and a plurality of heat-transfer promoting projections integrally formed with the internal surface and protruding inwardly from the internal surface,wherein a hollow cylindrical insert is set inside the internal surface of the turbine airfoil, the cooling air is supplied to an inside of the insert, and the insert has a plurality of impingement holes for impingement-cooling the internal surface,wherein the plurality of heat-transfer promoting projections is set to be slightly shorter than a spacing between the internal surface of the turbine airfoil and the external surface of the insert, and wherein the heat-transfer promoting projections are formed in a cylindrical shape;
- the film-cooling holes and the impingement holes are aligned to each other along the flow of the hot gas, the film-cooling holes are arranged at a pitch P2 along the flow of the hot gas, the impingement holes are arranged at a pitch P1 along the flow of the hot gas so as to be positioned midway between the film-cooling holes which are adjacent to each other along the flow of the hot gas; and
the film-cooling holes and the impingement holes are arranged at a same pitch Py in a direction perpendicular to the flow of the hot gas, and the heat-transfer promoting projections are positioned at a position deviated from the film-cooling holes and the impingement holes in a direction perpendicular to the flow of the hot gas.
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Accused Products
Abstract
A cooling structure of a turbine airfoil cools a turbine airfoil (10) exposed to hot gas (1), using cooling air (2) of a temperature lower than that of the hot gas. The turbine airfoil (10) includes an external surface (11), an internal surface (12) opposite to the external surface, a plurality of film-cooling holes (13) blowing the cooling air from the internal surface toward the external surface to film-cool the external surface, and a plurality of heat-transfer promoting projections (14) integrally formed with the internal surface and protruding inwardly from the internal surface. The turbine airfoil further includes a hollow cylindrical insert (20) which is positioned inside the internal surface of the turbine airfoil and to which the cooling air is supplied. The insert has a plurality of impingement holes (21) for impingement-cooling the internal surface (12).
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Citations
5 Claims
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1. A cooling structure of a turbine airfoil which cools a turbine airfoil exposed to hot gas using cooling air of a temperature lower than that of the hot gas,
the turbine airfoil comprising an external surface exposed to the hot gas, an internal surface opposite to the external surface and cooled by the cooling air, a plurality of film-cooling holes extending between the internal surface and the external surface and blowing the cooling air from the internal surface toward the external surface to film-cool the external surface, and a plurality of heat-transfer promoting projections integrally formed with the internal surface and protruding inwardly from the internal surface, wherein a hollow cylindrical insert is set inside the internal surface of the turbine airfoil, the cooling air is supplied to an inside of the insert, and the insert has a plurality of impingement holes for impingement-cooling the internal surface, wherein the plurality of heat-transfer promoting projections is set to be slightly shorter than a spacing between the internal surface of the turbine airfoil and the external surface of the insert, and wherein the heat-transfer promoting projections are formed in a cylindrical shape; -
the film-cooling holes and the impingement holes are aligned to each other along the flow of the hot gas, the film-cooling holes are arranged at a pitch P2 along the flow of the hot gas, the impingement holes are arranged at a pitch P1 along the flow of the hot gas so as to be positioned midway between the film-cooling holes which are adjacent to each other along the flow of the hot gas; and the film-cooling holes and the impingement holes are arranged at a same pitch Py in a direction perpendicular to the flow of the hot gas, and the heat-transfer promoting projections are positioned at a position deviated from the film-cooling holes and the impingement holes in a direction perpendicular to the flow of the hot gas. - View Dependent Claims (2, 3, 4, 5)
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Specification